JP2008062491A - Ejector mechanism and apparatus for molding non-conductor product having surface electric potential controlling function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector mechanism which can surely keep an ejector plate insulated from an ejector rod. <P>SOLUTION: The ejector rod 66 in which a part 76 including a contact surface with at least the ejector plate 58 is formed from an insulating material is driven in contact with the ejector plate 58 arranged forward/backward movably toward/from a non-conductor product 104 molded by a mold 14. By advancing the ejector plate 58, the non-conductor product 104 is ejected to be demolded by an ejector pin 60 supported by the ejector plate 58. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ejector mechanism and a non-conductor product molding apparatus having a function of controlling a surface potential, and in particular, is assembled to a molding die for molding a predetermined non-conductor product. The present invention relates to an ejector mechanism for ejecting and releasing a non-conductive product to be molded, and a non-conductive product molding apparatus having a function of controlling the surface potential, which is assembled with such an ejector mechanism. .

  In general, so-called non-conductor products made of non-conductor (insulator) materials such as resin materials and rubber materials (hereinafter, products made of these non-conductor materials are referred to as non-conductor products), injection molding, extrusion molding, In the case of molding by sheet molding, press molding, compression molding, vacuum molding, pressure molding, or the like, or secondary processing, various molding dies according to these various molding methods are used. As is well known, when a molding process of a desired non-conductor product (mold molding process) is performed using such a molding die, the non-conductor product is in contact with it. Various charging phenomena such as contact charging, friction charging, peeling charging, rolling charging, collision charging, and the like are induced between the contact portion of the molding die to be performed, and static electricity is inevitably generated in the non-conductive product.

  For example, when a resin product which is a kind of non-conductor product is injection-molded, the molten resin material injected from the injection device is filled in the molding cavity of the injection mold and cooled and solidified there. When the desired resin product is molded, contact charging occurs between the cooled and solidified resin product and the cavity surface of the injection mold, and the resin product is released from the mold. When doing so, peeling electrification is induced between the cavity surface. As a result, for example, when the injection mold or the molten resin material is made of a general-purpose material, various potentials are generated in the molded resin product depending on the surface area of the product, the processing time, etc. Depending on the situation, high-voltage static electricity of -20 kV or more can be generated.

  In such injection molding, static electricity generated in the resin product due to a charging phenomenon generated between the injection mold and the resin product attracts foreign matters such as dust to the surface of the resin product. This is the cause of problems during surface treatment, and in addition to that, it causes mold release errors from resin molds, clogging of parts feeders, or malfunctions of inspection machines and measuring instruments. It is also a cause of various defective products and process troubles.

  Therefore, conventionally, after the non-conductive product including such a resin product is molded, the static potential of the non-conductive product is removed or reduced so that the surface potential of the non-conductive product becomes zero as much as possible. Thus, in other words, an extra step for controlling the surface potential of the non-conductive product must be performed so that the surface of the non-conductive product is prevented from being charged. This has led to a decline in product productivity. Moreover, the surface potential control of the non-conductor product by such static elimination is generally performed by irradiating the surface of the non-conductor product with ion air using an ionizer (static discharge device) (for example, Therefore, in order to remove not only the electric charge existing on the surface of the non-conductive product but also the electric charge floating on the surface from the inside, a long work is required. Depending on the working environment, uneven irradiation of ion air on the non-conductive product may occur, which may make uniform static elimination difficult. Above all, static elimination using this ionizer is carried out by post-processing on non-conductive products that have generated static electricity due to the molding process. It was impossible to prevent.

  In addition, by performing a known humidification treatment or antistatic agent treatment, the generation of static electricity in the non-conductor product during the molding process is prevented, and the surface potential of the non-conductor product is controlled (surface surface It is also conceivable to prevent charging). However, in the former process, if the mold forming process of the non-conductive product is performed under a high temperature such as injection molding, a sufficient effect cannot be expected, and the latter process is usually Since the surfactant is used, there is a concern that the surfactant may cause a defect in the post-process of the non-conductive product that has been molded.

  On the other hand, for example, first, after forming a sheet-like intermediate molded product by extrusion molding or the like, a plurality of target non-conductor products are processed so that the sheet-shaped intermediate molded product is processed into a predetermined shape by vacuum molding or the like. When molding in stages, static electricity is generated in both the intermediate molded product obtained in the middle and the non-conductive product finally obtained. In order to prevent the surface of the conductor product from being charged by static electricity, it may be effective to charge the surface of the intermediate molded product positively or negatively. That is, for example, when the target non-conductor product is molded in two stages, the surface of the molded intermediate molded product is charged with a polarity opposite to the static electricity generated during the secondary processing. In some cases, the surface potential of the finally obtained non-conductor product can be easily and efficiently controlled to zero or a value close thereto.

  However, when the surface potential of non-conductor products is controlled by static elimination processing, humidification processing, antistatic agent processing, etc. using an ionizer as described above, the surface potential of non-conductor products is set to a desired value other than zero or an approximate value thereof. It is extremely difficult to control the surface potential, and it has been impossible to make such a surface potential a value having a polarity opposite to that of static electricity generated during molding of a non-conductor product.

  Under such circumstances, the applicant of the present application previously formed or processed using various molding tools and processing tools (hereinafter collectively referred to as molding processing tools) including a molding die in Japanese Patent Application No. 2006-155641. A control device capable of controlling the surface potential of a non-conductive product to be a desired value at the time of molding and a non-conductor product molding processing device having such a surface potential control function have been proposed. These devices include an insulating means for preventing electrical grounding of a contact portion with a non-conductor product in a molding tool for forming a desired non-conductor product, and a non-conductor for at least the contact portion in the molding tool. A charge for controlling the surface potential of the product is applied at a polarity and voltage set based on the polarity and voltage of static electricity generated in the non-conductive product by a charging phenomenon generated between the contact portion and the contact portion. Charge applying means.

  If such a device is used, before the static electricity is generated in the non-conductive product, the polarity and voltage set based on the polarity and voltage of the static electricity at least at the contact portion with the non-conductive product in the molding tool. Can be charged to store the contact portion, thereby causing the surface of the non-conductive product molded using such a molding tool to be opposite to the contact portion of the molding tool. It becomes possible to store electricity at the same voltage as the polarity of. As a result, before the static electricity is generated in the non-conductive product, the charge of the same polarity as the static electricity or the opposite polarity is applied to the contact portion of the molding tool at an appropriate voltage based on the electrostatic voltage. It is possible to reliably control the surface potential of a non-conductor product after generation of static electricity to a desired value without incurring any deterioration in the quality, performance, etc. of the non-conductor product simply by applying it. It is.

  And, as described above, the non-conductive product molding device for non-conductive products and the non-conductive product forming device with the surface potential control function, which exhibits such excellent characteristics, is a non-conductive product to be molded. By controlling the surface potential of the non-conductive product molded in such a molding die, a molding die in which various charging phenomena occur between the (resin product) and the cavity surface is used as a molding tool. However, when an ejector mechanism for projecting and releasing a molded non-conductive product is assembled to the molding die, the following problems may occur.

  That is, in general, an ejector mechanism assembled to a molding die includes an ejector plate disposed so as to be able to advance / retreat toward a non-conductor product molded by the molding die, and an ejector plate supported by the ejector plate. It includes an ejector pin that protrudes and releases a non-conductive product by advancement of the plate, and an ejector rod that is driven in contact with the ejector plate to advance the ejector plate. The ejector plate, the ejector pin, and the ejector rod in the ejector mechanism are all formed using a metal material. Therefore, when the ejector pin or the ejector plate comes into contact with the molding die during the operation of the ejector mechanism, the electric charge applied to the molding die from the voltage applying means is discharged to the outside through the ejector rod in contact with the ejector plate. As a result, there is a concern that power storage of the molding die may be hindered or that the operation of the ejector mechanism may be adversely affected.

JP 2002-46147 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is that the insulation state between the ejector plate and the ejector rod can be advantageously ensured. In addition to a control device that controls the surface potential of a non-conductive product to be processed to a desired value, the control performance of the surface potential of the non-conductive product by such a control device is stable when assembled in a molding die. An ejector mechanism that has been improved so that it can be exerted, and such an ejector mechanism has been assembled so that a non-conductor product whose surface potential is controlled to a desired value can be formed and processed more advantageously. An object of the present invention is to provide a non-conductor product molding apparatus having a function of controlling electric potential.

  In the present invention, in order to solve the problem relating to the ejector mechanism, the gist of the invention is that it is assembled to a molding die for molding a predetermined non-conductor product, and molded with the molding die. An ejector plate disposed so as to be capable of moving forward / backward toward the non-conductive product to be processed, and an ejector pin supported by the ejector plate so that the non-conductive product is protruded and released by the advance of the ejector plate; In an ejector mechanism configured to include an ejector rod that is driven in contact with the ejector plate to advance the ejector plate, an insulating material is formed on at least a portion of the ejector rod that includes a contact surface with the ejector plate. The ejector mechanism is characterized by being formed by using.

  In addition, according to one of the preferred embodiments of the ejector mechanism according to the present invention, the ejector mechanism further includes a driving unit that drives the ejector rod in a direction in which the ejector plate is advanced. The ejector rod is attached to the drive means in a detachable manner, and the attachment portion of the ejector rod to the drive means is formed using a metal material.

  Moreover, according to another desirable aspect of the ejector mechanism according to the present invention, the attachment portion of the ejector rod to the drive means has a screw portion for screwing the drive means to the drive means. Is done.

  In addition, in the present invention, in order to solve the problems related to the molding processing apparatus for non-conductor products having the function of controlling the surface potential, the gist of the present invention is when molding non-conductor products. In addition, a non-conductor product molding apparatus having a function of controlling the surface potential of the non-conductor product in which static electricity is generated by a charging phenomenon, wherein the non-conductor product is in contact with the non-conductor product. A contact mold having electrical conductivity that causes the charging phenomenon in between, a molding die for molding the non-conductor product, and electrical grounding of the contact section in the molding die The polarity and voltage of the static electricity generated in the non-conductor product by the charging phenomenon, with respect to the insulating means and at least the contact portion of the molding die for controlling the surface potential of the non-conductor product. And based on The surface potential is characterized in that the ejector mechanism having the above-described structure is assembled to the molding die, and includes a charge applying means for applying the applied polarity and voltage. It is in a non-conductor product forming apparatus having a function of controlling the above.

  That is, in the ejector mechanism according to the present invention, the ejector rod is brought into contact with the ejector plate in the portion formed using the insulating material, whereby the ejector rod and the ejector plate can be brought into contact with each other. The space can be reliably insulated.

  Therefore, in the ejector according to the present invention, it is assembled with a control device for controlling the surface potential of the non-conductive product to be molded to a desired value with respect to the molding die for molding the non-conductive product. When a predetermined charge is applied to the molding die by the control device, even if the ejector plate or ejector pin contacts the molding die, the charge applied to the molding die flows from the ejector plate into the ejector rod. Further, it is possible to effectively eliminate the discharge to the outside through the ejector rod, thereby preventing the storage of the molding die or adversely affecting the operation of the ejector mechanism.

  Therefore, in the ejector rod according to the present invention as described above, it is assembled with a control device for controlling the surface potential of the nonconductive product to be molded to a desired value with respect to the molding die for molding the nonconductive product. When this is done, the control performance of the surface potential of the non-conductor product by such a control device can be exhibited very stably and reliably.

  Further, in the non-conductor product molding apparatus having the function of controlling the surface potential according to the present invention, the ejector mechanism that exhibits the excellent characteristics as described above, and the surface potential of the non-conductor product to be molded. And a control device for controlling the value to a desired value are both assembled to a molding die for molding a non-conductor product. Therefore, the surface potential is controlled to a desired value, which makes it possible to reliably eliminate various troubles and troubles that have occurred during molding due to electrostatic charging. And can be molded stably.

  Hereinafter, in order to clarify the present invention more specifically, the configuration of the present invention will be described in detail with reference to the drawings.

  First, in FIG. 1, an injection molding apparatus (injection molding machine) for a resin product, which is an embodiment of a molding apparatus for a non-conductive product having a surface potential control function, to which an ejector mechanism according to the present invention is assembled, In its main part, it is schematically shown. As is clear from FIG. 1, the injection molding apparatus according to the present embodiment includes an injection apparatus 10, a mold clamping apparatus 12, and a molding die 14. Here, after the molding die 14 is attached to the mold clamping device 12 so as to be insulated from the injection device 10 and the mold clamping device 12, the surface potential of the resin product to be injection-molded is set to a desired value. The function to control to the value can be exhibited.

  More specifically, the injection device 10 has a structure similar to the conventional one in which a predetermined resin material is kneaded with a screw (not shown) in the heating cylinder 16 and melted in the heating cylinder 16. The formed resin material is injected from a metal nozzle 18 attached to the tip of the heating cylinder 16.

  Similarly to the conventional apparatus, the mold clamping device 12 is also opposed to the fixing plate 22 fixed to the distal ends of a plurality of tie bars 20 having a predetermined length with a predetermined distance from the fixing plate 22. And a movable plate 24 supported by a plurality of tie bars 20 while being movable in the opposite direction. Further, a hydraulic cylinder (not shown) is installed on the back side of the movable plate 24 (the side opposite to the side facing the fixed plate 22), and the tip of the ram 26 that is projected / retracted by the operation of the hydraulic cylinder, It is attached to the back surface of the movable plate 24. As a result, the movable plate 24 is moved closer to or away from the fixed plate 22 as the first ram 26 protrudes / retracts based on the operation of the hydraulic cylinder.

  The molding die 14 is composed of two divided dies, a movable die 28 and a fixed die 30, and is positioned between the movable plate 24 and the fixed plate 22 of the mold clamping device 12. The movable mold 28 and the fixed mold 30 are fixedly attached to the movable plate 24 and the fixed plate 22 in an insulated state.

  That is, the movable mold 28 is configured to further include the movable mold plate 32, the movable substrate 34, and the spacer block 36. The movable side mold plate 32 has a rectangular flat plate shape or a rectangular block shape as a whole, and is arranged to face the fixed mold 30. In addition, a cavity forming recess 38 that opens toward the fixed mold 30 is formed on the surface of the movable side mold plate 32 facing the fixed mold 30 with an inner surface shape corresponding to the outer shape of the target resin product. Has been.

  The movable side substrate 34 has a rectangular flat plate shape that is slightly larger than the movable side template 32, and is separated from the movable side template 32 on the side of the movable plate 24 that sandwiches the movable side template 32 with the fixed mold 30. It is positioned. The spacer block 36 has a rectangular tube shape having the same size and a low height as the movable side mold plate 32, and is interposed between the movable side mold plate 32 and the movable side substrate 34 so that they are integrated. It is connected and arranged. In addition, the movable side substrate 34 has a size that is slightly larger than the movable side mold plate 32 having the same size as the spacer block 36, so that the outer peripheral portion extends over the entire circumference. The block 36 is positioned in a state where it protrudes laterally from the connecting surface with the movable side substrate 34.

  In this case, the movable-side substrate 34 of the movable mold 28 has a movable-side insulating plate 40 as an insulating means that has a thicker flat plate shape that is slightly larger than the movable-side substrate 34. The movable plate 24 is superposed and arranged in a non-contact state. Further, in such an arrangement state, the movable plate 24 is fixed to the movable plate 24 by fixing bolts 39 made of an insulating material such as a ceramic bolt, which are inserted into a plurality of locations on the outer peripheral portion protruding from the spacer block 36 of the movable substrate 34. Thus, the entire movable mold 28 is fixedly attached to the movable plate 24 in an insulated state.

  The movable insulating plate 40 used here is not particularly limited as long as it is made of an insulating material. For example, the movable insulating plate 40 is entirely made of a ceramic material such as alumina, polypropylene, polyethylene, or polycarbonate. A plate material made of a resin material such as ABS resin, a glass material, or a plate material whose surface is covered with a ceramic material, a resin material, or a glass material, or an inorganic / organic glass cloth laminated plate, etc. Can be used.

  On the other hand, the fixed mold 30 has a rectangular block shape as a whole, and is disposed opposite to the movable mold plate 32 of the movable mold 28. Then, the facing surface (molding surface) of the movable mold 28 against the movable mold plate 32 is brought into contact with the opposed surface of the movable mold plate 32 to the fixed mold 30 by the mold clamping operation of the mold clamping device 12 as will be described later. In contact therewith, a smooth cavity forming surface 42 covering the cavity forming recess 38 of the movable side mold plate 32 is formed. Furthermore, a relatively thick rectangular shape protrudes from the outer peripheral surface of the fixed die 30 at a predetermined height at the end opposite to the cavity forming surface 42 and continuously extends in the circumferential direction over the entire circumference. A plate frame-shaped outer flange portion 44 is integrally formed. The outer flange portion 44 is configured such that one surface in the thickness direction is flush with the surface opposite to the cavity forming surface 42 of the fixed mold 30.

  In addition, a sprue bushing 46 is embedded in the center of the fixed mold 30 so as to open on the surface opposite to the cavity forming surface 42 and is bolt-fixed. A sprue 48 communicating with the hole 47 is formed through the center so as to open in the cavity forming surface 42.

  And, such a fixed mold 30 is sandwiched between the fixed side insulating plate 50 as an insulating means having a thick flat plate shape slightly larger than that on the entire surface opposite to the cavity forming surface 42 side, A ceramic bolt or the like inserted through the outer flange portion 44 and the fixed-side insulating plate 50 is arranged in a non-contact state with the fixing plate 22 of the mold clamping device 12 in a non-contact state. The outer flange portion 44 is fixed to the fixing plate 22 by a plurality of fixing bolts 39 made of an insulating material. As a result, the entire fixed die 30 is attached to the fixed position in an insulated state with respect to the fixed plate 22.

  As long as the fixed-side insulating plate 50 interposed between the fixed mold 30 and the fixed plate 22 is made of an insulating material, the structure of the material is not particularly limited, and the movable mold 28 is not limited. The same material and structure as the movable side insulating plate 40 interposed between the movable plate 24 and the movable plate 24 can be used. In addition, a through-hole 52 is formed in the center of the fixed-side insulating plate 50 so as to penetrate the fixed-side insulating plate 50, and the fixed-side insulating plate 50 is interposed between the fixed mold 30 and the fixed plate 22. The through hole 52 is communicated with the inner hole 47 of the sprue bush 46 attached to the fixed mold 30.

  Further, the tip of the nozzle 18 of the injection device 10 inserted and inserted into the insertion hole 54 of the fixed plate 22 under the mounting state of the fixed mold 30 to the fixed plate 22 is in the fixed insulating plate 50. At the center of the surface on the side opposite to the fixed mold 30 side, the tip opening is communicated with the through hole 52, and the contact is positioned. As a result, the nozzle 18 of the injection device 10 and the fixed mold 30 are insulated from each other, and the molten resin material injected from the nozzle 18 is allowed to pass through the through-hole 52 of the fixed-side insulating plate 50 and the sprue bushing 46. The inside of the inner hole 47 and the inside of the sprue 48 of the fixed mold 30 can be made to flow in that order.

  Thus, in the injection molding apparatus of the present embodiment, the movable mold 28 is moved toward / away from the fixed mold 30 as the movable plate 24 approaches / separates the fixed plate 22 in the mold clamping device 12. The movable mold 28 and the fixed mold 30 are closed / opened and pressed. Then, the movable mold 28 and the fixed mold 30 are closed, and the opening of the cavity forming recess 38 in the movable mold plate 32 of the movable mold 28 is covered with the cavity forming surface 42 in the fixed mold 30. Accordingly, a molding cavity 56 having a shape corresponding to the target resin product is formed between the mold-matching surfaces of the movable mold plate 32 and the fixed mold 30 of the movable mold 28 (see FIG. 3).

  Further, under such a state where the movable mold 28 and the fixed mold 30 are aligned, the sprue 48 of the fixed mold 30 is opened in the molding cavity 56, and is thereby injected from the nozzle 18 of the injection apparatus 10. The molten resin material is introduced into the molding cavity 56 through the through hole 52 of the stationary insulating plate 50, the inner hole 47 and the sprue 48 of the sprue bush 46, and filled. Then, the molten resin material filled in the molding cavity 56 is cooled and solidified, so that a target resin product is molded (see FIGS. 4 and 5). As is clear from this, in this embodiment, the part including the movable side mold plate 32 of the movable mold 28 and the cavity forming surface 42 of the fixed mold 30 is a contact part with the resin product to be molded.

  In the present embodiment, an ejector mechanism for projecting the molded resin product and releasing it from the molding die 14 having such a structure is assembled, and this ejector mechanism is conventionally used. It is constructed with a special structure not seen in

  That is, the ejector mechanism includes a metal ejector plate 58 having a rectangular flat plate shape and disposed in the inner hole of the square cylindrical spacer block 36 in the movable die 28. Further, the ejector plate 58 is movable within the height range of the spacer block 36 in the axial direction of the spacer block 36, that is, in both directions of the movable template 32 side and the movable substrate 34 side. . In other words, the ejector plate 58 has a molding cavity 56 within a range from a position where one end surface in the thickness direction contacts the movable mold plate 32 to a position where the other end surface contacts the movable substrate 34. It is possible to advance / retreat toward the resin product to be molded inside.

  Further, a plurality of elongated metal ejector pins 60 are supported on the ejector plate 58 so as to stand on the end surface on the movable side mold plate 32 side, and are attached to the ejector plate 58 so as to be movable together. Yes. Each of the ejector pins 60 opens in the facing surface of the movable side mold plate 32 facing the movable plate 24 and the bottom surface of the cavity forming recess 38, and is straight in the facing direction of the movable mold 28 and the fixed mold 30. Are inserted into a plurality of pin insertion holes 62 formed so as to extend. Note that the length of the ejector pin 60 (the protruding height of the ejector plate 58 from the surface on the movable mold plate 32 side) is longer than the extended length of the pin insertion hole 62 by a predetermined amount. ing.

  Thus, here, as the ejector plate 58 advances / retreats, each ejector pin 60 can be moved in each pin insertion hole 62 in its extending direction. Then, when the ejector plate 58 is brought into contact with the movable side mold plate 32 by advancing, the tip of each ejector pin 60 is projected from the bottom surface of the cavity forming recess 38 at a predetermined length. On the other hand, when the ejector plate 58 is brought into contact with the movable-side substrate 34 by retreating, the tip portions of the ejector pins 60 are drawn into the pin insertion holes 62.

  Further, a step portion that enlarges the diameter of the opening side portion of the surface of the movable side mold plate 32 facing the movable plate 24 is provided in the intermediate portion in the length direction of the pin insertion hole 62 through which the ejector pin 60 is inserted. The compression coil spring 64 is accommodated in the large-diameter portion 63 of the pin insertion hole 62. The compression coil spring 64 is in a pre-compressed state, and is respectively engaged with a stepped portion serving as a bottom surface of the large diameter portion 63 in the pin insertion hole 62 and a surface facing the movable side mold plate 32 of the ejector plate 58. Have been combined.

  On the other hand, a plurality of ejector rods 66 are brought into contact with each other on the front surface of the ejector plate 58 facing the movable substrate 34. Each of the ejector rods 66 is a round bar having a thickness and length sufficiently larger than the ejector pin 60, and is provided at the center of each of the movable side substrate 34, the movable side insulating plate 40, and the movable plate 24. The holes 68, 70, 72 are extended to the back side of the movable plate 24, and are further plunged into the first ram 26 attached to the back surface of the movable plate 24. The protruding portion of the ejector rod 66 into the first ram 26 is fixed to the front end surface of the second ram 74 disposed inside the first ram 26. The second ram 74 is projected / retracted integrally with the first ram 26 based on the operation of a hydraulic cylinder (not shown) that causes the first ram 26 to project / retract. Based on the operation of a built-in hydraulic cylinder (not shown), the first ram 26 can be protruded / retracted relative to the first ram 26. As a result, each ejector rod 66 is configured to be advanced / retracted toward the movable side mold plate 32 as the first ram 26 and the second ram 74 project / retract.

  Thus, in the ejector mechanism having such a structure, the second ram 74 is integrally or relatively projectingly operated with the first ram 26 so that each ejector rod 66 is advanced, whereby the ejector plate. 58 is pushed by the ejector rods 66 and moved forward against the urging force of the compression coil spring 64 to a position where it abuts against the movable side mold plate 32, so that the tip of each ejector pin 60 is moved forward. The cavity forming recess 38 protrudes from the bottom surface. At this time, if a resin product that has been injection-molded is accommodated in the cavity forming recess 38, the resin product is projected at the tip of each ejector pin 60 and released. (See FIG. 5).

  In addition, the second ram 74 is integrally or relatively retracted with the first ram 26 so that each ejector rod 66 is retracted, so that the ejector plate 58 is moved by the urging force of the compression coil spring 64. The tip of each ejector pin 60 protruding from the bottom surface of the cavity forming recess 38 is retracted to a position where it abuts on the movable substrate 34 while maintaining the contact state with each ejector rod 66. The pin is inserted into the pin insertion hole 62. As is clear from these facts, in the present embodiment, the first ram 26 and the second ram 74 and the hydraulic cylinder for causing the first ram 26 and the second ram 74 to project / retract are configured as drive means.

  Here, when the movable mold 28 and the fixed mold 30 are opened by the drawing operation of the first ram 26 after the target resin product is molded in the molding cavity 56, first, the second ram 74 is retracted and moved integrally with the first ram 26, and before the retracting operation of the first ram 26 stops, that is, the movable mold 28 and the fixed mold 30 reach the predetermined mold opening position. The second ram 74 is protruded relative to the first ram 26 before the mold is opened.

  In this embodiment, in particular, one axial side portion of the ejector rod 66 in this ejector mechanism is formed using a known insulating material, while the other side portion is more resistant than the insulating material. It is formed using a metal material having excellent impact properties. That is, a portion of the ejector rod 66 that is in contact with the ejector plate 58 is an insulating portion 76 made of an insulating material over a predetermined length, and is located on the side fixed to the second ram 74. A portion other than the insulating portion 76 is a metal portion 78 made of a metal material.

  As is clear from FIG. 2, in the metal portion 78 of the ejector rod 66, a male screw portion 80 having a male screw engraved on the entire outer peripheral surface is formed at a predetermined length at the center of the end surface on the second ram 74 side. On the other hand, a female screw hole 82 is provided with a predetermined depth on the opposite end surface. In addition, the metal material similar to the formation material of the ejector rod which the conventional ejector mechanism has is used for the metal material which forms this metal part 78. FIG.

  On the other hand, the insulating portion 76 is formed using, for example, the same insulating material as the forming material of the movable and fixed insulating plates 40 and 50 to be put on the surface, or against the surface of a metal bar. Thus, the insulating material such as a ceramic material or a resin material is coated and formed with a predetermined thickness so that the insulating property can be exhibited. In addition, in the insulating portion 76, the end surface on the ejector plate 58 side is a flat contact surface 84 corresponding to the flat end surface of the ejector plate 58, but at the center of the end surface on the opposite side. The male screw portion 86 in which a male screw that is screwed into the female screw hole 82 of the metal portion 78 is engraved on the entire outer peripheral surface is integrally protruded with a length shorter than the depth of the female screw hole 82.

  The male screw portion 86 of the insulating portion 64 is screwed into the female screw hole 82 of the metal portion 78, and the insulating portion 76 is attached to the metal portion 78. Thus, the ejector rod 66 is detachably attached to the insulating portion 76 exhibiting insulating properties and the metal portion 78 having higher impact resistance than the insulating portion 64, and is integrated with an integrated assembly. Further, the end surface on the insulating portion 76 side in this integrally assembled product is the contact surface 84, and the male screw portion 80 is provided on the end surface on the metal portion 78 side. Alternatively, the adhesive part 64 and the metal part 78 may be attached in a non-detachable manner by screwing the male screw part 86 into the female screw hole 82 of the metal part 78 after applying an adhesive or the like to the outer peripheral surface thereof. I can do it.

  Then, the ejector rod 66 having such a structure is screwed into the female screw hole 87 provided in the distal end surface of the second ram 74 in the male screw portion 80 of the metal portion 78 and the insulating portion 76. The entire contact surface 84 is in contact with the ejector plate 58. Thus, the ejector rod 66 is attached to the second ram 74 so as to be detachable by screw fastening and to be movable together therewith. Further, the ejector rod 66 and the ejector plate 58 are insulated from each other, so that the ejector plate 58 and the ejector pin 60 are brought into contact with the spacer block 36, the movable mold plate 32, and the movable substrate 34 of the movable mold 28. Even in this case, an insulating state (electrically non-grounded state) with respect to the movable plate 24 and the ejector mechanism of the movable mold 28 is ensured. As is clear from the above, here, the entire mounting portion of the ejector rod to the driving means is constituted by the male threaded portion 80 of the metal portion 78.

  In the present embodiment, as shown in FIG. 1, a negative charge having the same polarity as the static electricity generated in the resin product to be injection-molded with respect to the movable mold 28 attached in an insulated state to the movable plate 24. A high voltage power supply device 88 is electrically connected as a charge applying means for applying. That is, the high-voltage power supply device 88 has a known structure that can supply high-voltage negative charges of about 1 to 30 kV, for example. In addition, for example, a crimp terminal or the like (not shown) is attached to the distal end portion of the lead wire 60 extending from the high-voltage power supply device 88. Then, the crimp terminal attached to the tip of the lead wire 90 is attached to the movable side mold plate 32 with a bolt or the like screwed into the side surface of the movable side mold plate 32 of the movable mold 28, etc. The power supply device 88 and the movable mold 28 are electrically connected. The high voltage power supply 88 is grounded by a ground wire 92.

  The high-voltage power supply 88 is also electrically connected to a controller 94 as a control means for controlling the operation. Further, the controller 94 detects the closed state of the movable mold 28 and the fixed mold 30 and the complete mold open state as described above, and is attached to the movable plate 24, the fixed plate 22 or the like, for example, a limit switch or the like. The sensor element (not shown) is electrically connected. In the controller 94, when the sensor element such as a limit switch detects that the movable mold 28 and the fixed mold 30 are closed, the high-voltage power supply device 88 is operated. From this mold closed state, the movable mold 28 and the fixed mold 30 are completely opened, that is, the movable mold 28 and the fixed mold 30 are moved to a preset mold opening position and molded. The high voltage power supply 88 is stopped so that the high voltage power supply 88 is stopped when it is detected that the molded resin product is ejected from the cavity forming recess 38 to the outside by the ejector pin 60 and released. Can be controlled. Further, the controller 94 is provided with an operation knob 96 as a changing means. When the operation knob 96 is picked and rotated, the negative charge voltage supplied from the high-voltage power supply device 88 is arbitrarily set. Is set in advance, or the set value can be changed or adjusted.

  Thus, here, when the movable mold 28 and the fixed mold 30 are in the closed state, negative charges are applied to the movable side mold plate 32 of the movable mold 28 from the high voltage power supply device 88 by the operation knob 96. Is automatically applied (supplied) at a voltage preset by a rotating operation. Further, when the movable mold 28 and the fixed mold 30 are opened from the closed state of the movable mold 28 and the fixed mold 30, and the resin product is released from the mold, the movable mold 28 is moved from the high voltage power supply device 88. The application of negative charges to the movable mold plate 32 is automatically stopped.

  As described above, the movable mold 28 is always insulated from the mold clamping device 12 (movable plate 24), the ejector mechanism, and the like by the movable insulating plate 40 and the insulating portion 76 of the ejector rod 66. Furthermore, the fixed mold 30 is also always insulated from the mold clamping device 12 (fixed plate 22) by the fixed insulating plate 50. Accordingly, the negative charge is automatically applied from the high-voltage power supply device 88 to the movable side mold plate 32 at a desired voltage in a state where the movable mold 28 and the fixed mold 30 are closed. The fixed mold 30 is automatically charged negatively at the same voltage as the negative charge applied to the movable mold plate 32. At this time, since the nozzle 18 of the injection apparatus 10 and the fixed mold 30 are also insulated by the fixed insulating plate 50, the electric charge stored in the fixed mold 30 flows into the metal nozzle 18. Thus, it is not released from the fixed mold 30.

  In addition, the movable side mold plate 32 and the fixed mold 30 of the movable mold 28 are in the same state as the lead wire 90 of the high-voltage power supply device 88 in that the ground wire 98 as a grounding means for electrically grounding them. Are connected to each other. Further, in the middle of each ground wire 98, a switch 100 as a switching means for switching the ground wire 98 between a conductive state and a non-conductive state is provided. Each of the switches 100 is also electrically connected to the controller 94, and the controller 94 activates / stops the high-voltage power supply 88 (supply of negative charges from the high-voltage power supply 88 to the movable side mold plate 32). Automatically start / stop).

  In other words, here, the movable mold 28 and the fixed mold 30 are closed, and the controller 94 starts supplying negative charges from the high-voltage power supply device 88 to the movable mold plate 32. 100 is opened, and each ground wire 98 is made non-conductive, so that the movable mold 28 and the fixed mold 30 are automatically insulated. In addition, the movable mold 28 and the fixed mold 30 are opened, and the resin product is released, and the controller 94 stops the supply of negative charges from the high-voltage power supply device 88 to the movable mold plate 32. At the same time, each switch 100 is closed and each ground wire 98 is made conductive, so that the movable mold 28 and the fixed mold 30 are automatically grounded. The electric charges stored in the movable mold 28 and the fixed mold 30 are released by the grounding of the movable mold 28 and the fixed mold 30 by the closing operation of the respective switches 100.

  Thus, when a target resin product is molded using the injection molding machine having such a structure, for example, the operation is performed as follows.

  That is, first, as shown in FIG. 3, the movable plate 24 is moved close to the fixed plate 22 by the projecting operation of the first ram 26 of the mold clamping device 12. Clamp it. Thus, a molding cavity 56 is formed between the mold mating surfaces of the movable mold 28 and the fixed mold 30.

  Next, as shown in FIG. 4, a molten resin material 102 that is a forming material of the target resin product is injected from the nozzle 18 of the injection device 10. Then, the molten resin material 102 is introduced and filled into the molding cavity 56 by flowing the through hole 52 of the fixed insulating plate 50, the inner hole 47 of the sprue bushing 46, and the sprue 48.

  Thereafter, as shown in FIG. 5, the molten resin material 102 filled in the molding cavity 56 is cooled and solidified to mold the desired resin product 104. Subsequently, the first ram 26 of the mold clamping device 12 is retracted to move the movable plate 24 away from the fixed plate 22 and the movable mold 28 and the fixed mold 30 are opened. Further, when performing this mold opening, the first ram 26 and the second ram 74 are drawn and moved together until the middle of the mold opening, and the ejector plate 66 and the ejector plate 58 are attached to the compression coil spring 64. Retreat as a unit by force. Then, the second ram 74 is protruded and moved from the time when the distance between the movable die 28 and the fixed die 30 reaches a predetermined size until the retracting movement of the first ram 26 is completed, and the ejector rod 66 is moved. And the ejector plate 58 are moved forward together. As a result, the resin product 104 is ejected from the cavity forming recess 38 to the outside by the ejector pins 60, the first ram 26 reaches the limit position of the pulling movement, and the movable mold 28 and the fixed mold 30 are completely connected. When the mold is open, the resin product 104 is completely released from the molding die 14.

  Thus, in this case, in the series of molding operations of the resin molded product 104 as described above, the mold clamping device 12 is in contact with the movable mold 28 and the fixed mold 30 shown in FIG. The switch 100 in the middle of the ground wire 98 connected to each of the movable side mold plate 32 of the insulated movable mold 28 and the fixed mold 30 of the fixed mold 30 is opened by the controller 94 and fixed to the movable mold 28. The mold 30 is automatically and reliably electrically ungrounded. At the same time, the high-voltage power supply device 88 is activated by the controller 94, and negative charges are previously applied from the high-voltage power supply device 88 to the movable side mold plate 32 of the movable mold 28 by the operation on the operation knob 96. It is automatically applied at the set voltage. Thereby, the entire movable mold 28 and the fixed mold 30 of the fixed mold 30 are negatively charged with the same potential as the negative charge applied from the high voltage power supply device 88. At this time, even if the ejector pin 60 and the ejector plate 58 come into contact with the movable die 28, the ejector plate 58 and the ejector rod 66 are insulated by the insulating portion 76. From there, it does not flow into the ejector mechanism or the mold clamping device 12.

  It should be noted that when negative charges are applied from the high-voltage power supply device 88 to the movable side mold plate 32 of the movable mold 28, the current value is desirably set to zero as much as possible. This is because it is advantageous for an operator to receive an electric shock even if an operator or the like accidentally contacts the molding die 14 while a negative charge is being applied to the molding die 14. This is because it is eliminated and safe work can be secured. Further, as described above, in the present embodiment apparatus, the controller 94 performs the opening / closing operation of the switches 100, 100 provided in the middle of the ground wires 98, 98 connected to the movable mold 28 and the fixed mold 30, respectively. It is automatically controlled. Therefore, as shown in FIG. 5, when the movable mold 28 and the fixed mold 30 are completely opened, and the resin product 104 is released from the molding die 14, the movable mold is immediately used. 28 and the fixed mold 30 are grounded, and negative charges stored in the movable mold 28 and the fixed mold 30 are automatically released.

  When the resin product 104 is molded as shown in FIG. 4 in a state where a negative charge is applied from the high-voltage power supply device 88 to the movable mold 28, the resin product 104 is melted in the molding cavity 56 in the molten resin material 102. The movable mold 28 (movable side mold plate 32) and the fixed mold 30 that form the molding cavity 56, which are negatively charged by the application of a negative charge from the high-voltage power supply device 88, until being molded by cooling and solidifying, Touched. Therefore, the resin product 104 cooled and solidified in the molding cavity 56 is charged positively opposite to the movable die 28 or the stationary die 30 whose surface is negatively charged due to a polarization phenomenon or the like caused in the inside. You will be tempted.

  As shown in FIG. 5, when the molded resin product 104 is released from the molding die 14, the inner surface of the molding cavity 56 (the inner peripheral surface of the cavity forming recess 38 in the movable side mold plate 32, and Peeling occurs between the cavity forming surface 42) of the fixed mold 30 and the resin product 104, and negative static electricity is generated on the surface of the resin product 104. However, the negative charge in the static electricity is canceled by the positive charge charged on the surface of the resin product 104.

  Therefore, here, the surface potential of the resin product 104 after the mold release is determined according to the voltage of the negative charge applied to the movable mold 28 from the high-voltage power supply device 88 at a voltage preset by the operation on the operation knob 96. The desired value can be controlled.

  Specifically, a negative charge having a voltage larger by a predetermined amount than the electrostatic voltage generated in the resin product 104 due to release charging by mold release is transferred from the high voltage power supply device 88 to the movable mold 28 (movable side mold plate 32). If applied, the surface potential of the resin product 104 after release can be made as zero as possible, and the charged state of the surface of the resin product 104 can be eliminated. Further, if a negative charge having a voltage sufficiently higher than a voltage larger than the electrostatic voltage by a predetermined amount is applied from the high-voltage power supply device 88 to the movable mold 28, the surface of the resin product 104 after the release. It is possible to keep the potential positive. In order to set the surface potential of the resin product 104 to a desired value, the specific voltage of the negative charge applied from the high-voltage power supply device 88 to the movable mold 28 can be changed, for example, by variously changing the voltage applied to the negative charge. However, it is set in advance based on the results obtained by repeatedly performing the test for molding the target resin product 104.

  Thus, the intended resin product 104 is molded with a surface potential controlled according to the negative charge voltage applied from the high-voltage power supply device 88 to the movable mold plate 32 of the movable mold 28. It becomes.

  Thus, in the injection molding apparatus of the present embodiment, for example, without performing any special operation or processing unrelated to the injection molding operation such as humidification processing or antistatic processing using an antistatic agent. Therefore, without adding extra conditions and post-processing required for the execution of such special processing, the movable die 28 is simply connected from the high-voltage power supply device 88 in parallel with the conventional injection molding operation. In addition, the surface potential of the molded resin product 104 can be easily and reliably set, for example, so that the surface potential becomes zero as much as possible by performing an operation of applying a negative charge at a preset voltage. It becomes possible to control.

  Therefore, according to this embodiment as described above, the resin product 104 whose surface potential is controlled to a desired value can be molded extremely advantageously without causing any deterioration in quality, performance, or the like. As a result, various troubles and troubles caused by static electricity generated in the resin product 104 can be effectively eliminated during the molding process of the target resin product 104 or in subsequent processes. It becomes.

  In addition, in the present embodiment, when the movable mold 28 is charged by applying electric charges to the movable mold plate 32 in a state where the movable mold 28 and the fixed mold 30 are aligned, the ejector pin 60 of the ejector mechanism is used. Even if the ejector plate 58 is brought into contact with the movable die 28, the ejector rod 66 is positioned in contact with the ejector plate 58 by the insulating portion 76, so that the stored charge of the movable die 28 is The rod 66 can be advantageously prevented from flowing into the ejector mechanism or the mold clamping device 12. Therefore, the storage of the movable mold 28 and the fixed mold 30 is hindered, and the electric charge flowing into the ejector mechanism and the mold clamping device 12 through the ejector rod 66 adversely affects the operation of the ejector mechanism and the mold clamping device 12. In addition, the flow of electric charge into the ejector mechanism and the mold clamping device 12 obstructs the work of the operator who performs the molding work of the target resin product 104. Can be neglected.

  Therefore, in this embodiment as described above, the resin product 104 whose surface potential is controlled to a desired value can be molded more stably and reliably.

  In the present embodiment, the portion of the ejector rod 66 including the entire contact surface 84 with the ejector plate 58 is the insulating portion 76, while the female screw hole provided in the second ram 74 is provided. A portion including the male screw portion 80 that is screwed into and attached to the 87 is a metal portion 78 made of a metal material that has better impact resistance than the insulating portion 76. Therefore, unlike the case where the entire ejector rod 66 is made of an insulating material, when an impact load is generated when the male screw portion 80 is screwed into the female screw hole 87 of the second ram 74, the male screw The fear that the portion 80 is broken or damaged can be solved very effectively.

  Therefore, in this embodiment as described above, the replacement work of the ejector rod 66 can be performed more smoothly. And it can greatly contribute to the smoothing of the molding operation of the target resin product 104 controlled so that the surface potential becomes a desired value.

  Furthermore, in this embodiment, the operation / stop of the high-voltage power supply device 88 is automatically controlled by the controller 94 based on the mold opening / closing of the molding die 14, so that the movable mold 28 and the fixed mold 30 can be connected. Since the power storage operation is automatically performed, the resin product 104 having a desired surface potential can be molded industrially advantageously with more efficient and excellent manufacturability.

  Furthermore, in this embodiment, when the molding die 14 is opened and the molded resin product 104 is released, the charges stored in the movable mold 28 and the fixed mold 30 are automatically generated. In addition, the movable mold 28 and the fixed mold 30 are not charged until they are closed again. For this reason, even if an operator or the like touches the molding die 14 after the molding of the resin product 104 and before the molding of another resin product 104 is started, the worker may get an electric shock. This is advantageously eliminated and safety can be advantageously ensured.

  The specific configuration of the present invention has been described in detail above. However, this is merely an example, and the present invention is not limited by the above description.

  For example, in the above-described embodiment, the surface potential of the resin product 104 is controlled to a desired value by applying a negative charge to the movable mold 28 of the molding die 14 from the high-voltage power supply device 88 serving as a charge application unit. However, the polarity of the charge applied from the charge applying means to the molding die is not limited to this. For example, if the surface potential of the target resin product is set to zero as much as possible, or if such surface potential is opposite to the polarity of the static electricity generated in the resin product, it is the same as the static electricity. The polarity charge is applied to the molding die from the charge application means, and when the surface potential of the target resin product is the same polarity as the static electricity, the polarity is opposite to the static electricity. This charge is applied to the molding die from the charge applying means.

  In addition, the voltage of the charge applied from the charge applying means to the molding die is also appropriately determined according to the desired voltage of the surface charge of the resin product.

  Further, in addition to or instead of the movable mold 28, the high voltage power supply device 88 is connected to the fixed mold 30 so that electric charges are directly applied to both the movable mold 28 and the fixed mold 30. Alternatively, it is of course possible to apply a negative charge directly only to the fixed mold 30 and indirectly apply the charge to the movable mold 28 through the fixed mold 30.

  Furthermore, the movable mold 28 and the fixed mold 30 of the molding die 14 only need to be prevented from being electrically grounded at least at the contact portion with the resin product 104.

  Moreover, the movable side 28 and the fixed side insulating plates 40 and 50 as insulating means respectively interposed between the movable mold 28 and the movable plate 24 and between the fixed mold 30 and the fixed plate 22 are provided in the movable mold 28. Needless to say, the shape, size, material, etc. are not particularly limited as long as they can reliably insulate between the movable plate 24 and the movable plate 24 or between the fixed mold 30 and the fixed plate 22. That's where it is.

  Furthermore, the charge applying means is not limited to the exemplified high voltage power supply device 88, and only the negative charge and the positive charge are applied to the movable side mold 32 and the like. And, according to the polarity of static electricity generated in the resin product 104 and the value of the surface potential of the resin product 104 to be controlled from among those that can selectively apply positive and negative charges by external operation. Thus, those having a conventionally known structure can be appropriately selected and used.

  Moreover, in the said embodiment, although the ejector rod 66 was comprised with the insulation part 76 and the metal part 78, the whole may be formed with an insulating material and may be comprised only with the insulation part 76. FIG.

  Even when the ejector rod 66 is composed of the insulating portion 76 and the metal portion 78, the structure in which the insulating portion 76 and the metal portion 78 are integrated, and the size of the insulating portion 76 are the same as those of the ejector plate 58. Of course, the present invention is not limited to the examples as long as the insulation state between them can be secured.

  Furthermore, as the mounting structure for attaching the ejector rod 66 to the driving means such as the second ram 74, a structure for detachably mounting or a known mounting structure for detachably mounting can be appropriately selected and employed.

  Further, the molding die is not limited to a plurality of divided molds, and it may be nothing but a single mold.

  In addition, the present invention provides various molding dies for molding a non-conductor product other than a resin product, such as a rubber product, in addition to a molding die for injection molding of a resin product and an injection molding apparatus, and such Of course, the present invention can be advantageously applied to any molding apparatus including a molding die and having a function of controlling the surface potential.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is principal part explanatory drawing including one part cutaway figure which shows one Embodiment of the shaping | molding processing apparatus provided with the ejector mechanism according to this invention. It is a principal part expansion explanatory drawing in FIG. It is explanatory drawing which shows an example of the process of shape | molding a resin product using the shaping | molding processing apparatus shown by FIG. 1, Comprising: A movable mold | type and a fixed mold | type were match | combined and the state which formed the shaping | molding cavity is shown. Yes. FIG. 4 is a diagram for explaining a process performed subsequent to the process shown in FIG. 3, showing a state in which a molten resin material is filled in a molding cavity. It is a figure for demonstrating the process implemented following the process shown by FIG. 4, Comprising: The state which released the molded resin product is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Injection apparatus 12 Clamping apparatus 14 Molding die 18 Nozzle 22 Fixed plate 24 Movable plate 28 Movable mold 30 Fixed mold 32 Movable side mold plate 40 Movable side insulating plate 50 Fixed side insulating plate 56 Molding cavity 58 Ejector plate 60 Ejector pin 66 Ejector rod 74 Second ram 76 Insulating part 78 Metal part 80 Male thread part 84 Contact surface 88 High voltage power supply 94 Controller 102 Molten resin material 104 Resin product

Claims (4)

An ejector plate that is assembled to a molding die for molding a predetermined non-conductor product and is disposed so as to be capable of moving forward / backward toward the non-conductor product molded by the molding die, and supported by the ejector plate. An ejector pin that ejects the non-conductive product by advancing the ejector plate and releases it, and an ejector rod that is driven in contact with the ejector plate to advance the ejector plate. In the mechanism,
An ejector mechanism characterized in that at least a portion of the ejector rod including a contact surface with the ejector plate is formed using an insulating material.   Drive means for driving the ejector rod in a direction to advance the ejector plate, the ejector rod being detachably attached to the drive means, and attaching the ejector rod to the drive means The ejector mechanism according to claim 1, wherein the portion is formed using a metal material.   The ejector mechanism according to claim 2, wherein the attachment portion of the ejector rod to the driving means has a screw portion for screw-fastening to the driving means. A non-conductor product molding apparatus having a function of controlling the surface potential of a non-conductor product that generates static electricity due to a charging phenomenon when the non-conductor product is formed and is in contact with the non-conductor product. A molding die for forming the non-conductive product having a conductive contact portion that causes the charging phenomenon with the non-conductive product, and the contact portion in the molding die. Insulation means for preventing electrical grounding of the non-conductive product and an electric charge for controlling the surface potential of the non-conductive product for at least the contact portion of the mold are generated in the non-conductive product by the charging phenomenon. In what is configured to include a charge applying means to be applied at the polarity and voltage set based on the polarity and voltage of the static electricity to be tightened,
The ejector mechanism according to any one of claims 1 to 3, wherein the ejector mechanism is assembled to the molding die and has a function of controlling a surface potential. Conductor product forming equipment.

Images